Diverse vehicles equipped with fuel cells have been proposed. In any of these vehicles, electric power generated by the fuel cells is used to drive a motor. The driven motor outputs power to rotate an axle and wheels of the vehicle and accordingly move the vehicle. The vehicle has an exhaust pipe and an outlet arranged to discharge the exhaust gas from the fuel cells to the outside of the vehicle. Like conventional vehicles driven with power of an internal combustion engine, the outlet is typically located below the floor at a rear end of the vehicle body (see, for example, Japanese Patent Laid-Open No. 2002-289237). This arrangement of the outlet enables the exhaust gas discharged from the fuel cells and water produced in the course of power generation or by electrochemical reaction of hydrogen with oxygen (hereafter the exhaust gas and the produced water may collectively be referred to as ‘exhaust fluid’) to be directly emitted onto the road surface.
During a motion of the conventional vehicle equipped with the fuel cells according to the structure disclosed in Japanese Patent Laid-Open No. 2002-289237 on the water-covered road, however, the outlet may be blocked with water or sediment that is present on the road surface, so as to interfere with the smooth emission of the exhaust gas. This may stop power generation by the fuel cells and interfere with a further motion of the vehicle. The water or sediment flowed into the outlet may reach the inside of the fuel cells via piping and cause a damage or failure of the fuel cells. Namely the prior art techniques have no special consideration for potential troubles due to blockage of the outlet by an obstructing object, such as water or sediment, during a motion of the vehicle equipped with the fuel cells on the water-covered road.
This problem is not specifically found in the vehicles equipped with fuel cells but commonly arises in any of various moving bodies that are moved with electric power generated by fuel cells as a power source. Typical examples of such moving bodies include aircraft and boats and ships, as well as the vehicles.